Control of fungicidal plant diseases with trichloro-2-furamides



United States Patent 3,253,982 CONTROL OF FUNGICIDAL PLANT DISEASES WITHTRICHLORO-Z-FURAMIDES Edward Leon, Tonawanda, Edward D. Weil, Lewiston,and Jerome Linder, Niagara Falls, N.Y., assignors to Hooker ChemicalCorporation, Niagara Falls, N.Y., a corporation of New York No Drawing.Original application June 2, 1961, Ser. No. 114,321, now Patent No.3,158,624, dated Nov. 24, 1964. Divided and this application Nov. 23,1964, Ser. No. 413,279

2 Claims. (Cl. 167-33) This application is a division of our co-pendingapplication S.N. 114,321, filed June 2, 1961, for Heterocyclic AcidChloride and Process for Manufacture which application is now US. Patent3,158,624 granted on Nov. 24, 1964.

This invention relates to a novel oxygen-containing heterocycliccomposition of matter and to a novel method of preparing it.

More particularly, this invention describes trichloro-2- furoylchloride, a heretofore unreported compound useful as an organicintermediate for the preparation of pesticidal, fungicidal andherbicidal compositions of matter.

This invention in one of its composition aspects offers the advantage ofmaking available for the first time a reactive compound containing theuseful trichlorinated oxygen heterocyclic nucleus which readilyundergoes many reactions with substances containing a complementary orreceptive group such as the amines, alcohols, phenols and the like,whether the compound be aliphatic, aromatic or heterocyclic, saidproducts having value among other ways as pesticides and herbicides.While it is true that the trichloro-Z-furoic acid is known, theavailability of the much more reactive acid chloride ofiers manyadvantages over the free acid. For example, reactions where one of thereactants is an acid chloride will undergo all of the reactions that thefree acid will, including amination, esterification, hydrolysis, and thelike, and furthermore, will undergo ammonolysis or aminolysis to theamide which can only be made indirectly going through the acid. Inaddition, the acid chloride reacts more vigorously at lower reactiontemperatures, generally requires no catalysts and will often give betteryields than the acid. In this particular case, the trichloro-Z-furoicacid has little practical value as an intermediate since it can only beprepared through a costly multi-step synthesis starting with furoic acidin poor yield. Thus, to prepare the acid chloride through the classicalroute from the free acid is not advantageous here since it requires theobjectionable multi-step preparation of the acid plus an additional stepof reacting the acid with a phosphorus or sulfur halide or oxyhalide.This conversion step substantially adds to the cost of preparation andalso reduces the yield to a significant extent. Thus, introducing thetrichloro-Z-furan moiety in another molecule cannot be economically doneby any present known process since the present known method isunsatisfactory.

In its process aspect, this invention has the advantage of makingavailable a novel and simple one-step process from a commerciallyavailable starting material, which readily lends itself to commercialexploitation and produces the desired trichloro-Z-furoyl chloride ingood yield substantially free of impurities. This novel process involvesthe thermal re-arrangement of tetrachlorocoumalin(tetrachloro-ot-pyrone) to the desired trichloro-Z-furoyl chloride. Thestarting material, tetrachlorocoumalin, is a known commerciallyavailable material having a melt- 3,253,982 Patented May 31, 1966 ingpoint of 78.5 to eighty degrees centigrade. Its preparation has beendescribed by Roedig and Miirkl, Annalen der Chemie, 636, l-l8 (1960).

The novel re-arrangement reaction involved may be written as follows:

The'inventive process is advantageous and surprising in severalrespects. It is advantageous in that the process requires only one stepto go from a commercially available intermediate to the acid chloride ingood yield as compared to the multi-step preparation of the acid. It ismost unexpected and surprising that the acid chloride can be thusprepared considering that the conversion of y no other halo-coumalins tofuroyl chloride or its derivatives has been reported. It is alsosurprising that the reaction conditions are simple, requiring nocatalyst or other reagents, merely the application of heat and theseparation of product.

Yet another advantage of this invention in its process aspect is that itotters the means of introducing the herbicidally and pesticidallyvaluable trichloro-2-furan moiety in a molecule without resorting to acomplicated synthetic route or extreme reaction conditions. For example,the trichloro-2-furoyl chloride may be reacted with a broad group ofcompounds aromatic, aliphatic and heterocyclic, containing reactiveamino group. The structure of this type or reactant is HNR R where R andR', which may be the same or difierent, are chosen from the groupconsisting of hydrogen, alkyl, alkenyl, aryl, hydroxyl,oxygen-containing heterocycles, and other heterocyles.

The process of preparing this group of amides is, in most cases,analogous to well known and routine procedures, and is described in moredetail further in this application. The trichloro-Z-furoyl chloride isdissolved in an appropriate unreactive solvent such as benzene, toluene,ether, or ethylene chloride, for example, and the amine added withvigorous stirring to the acid chloride solution. Cooling can be providedwhere necessary. Where the amine is a solid, it is usually dissolved ina non-reactive organic solvent, but where the amine is a free flowingliquid no solvent is essential though a solvent may be added if desired.It is convenient to use two moles of the amine per mole of the acidchloride, forming one mole of the amine hydrochloride which may beremoved by filtration or by water extraction, leaving the product in thesolvent from which it may be isolated by evaporation or the addition ofa precipitating solvent. Other means of isolation will be obvious to oneskilled in the techniques of organic chemistry. Where the product isdestined for herbicidal use, no further purification is necessary,although for other purposes purification may be needed. In thoseinstances where pure product is desired, recrystallization,chromatography or the like may be resorted to.

Amongst the amides which may be made using the trichloro-Z-furoylchloride and the previously defined -NR R amino reactant are twodistinct groups having pronounced but different biological activities.

3 The first group of amides are trichloro-Z-furamides of the structure:

Cl-C-CCl ll C1C C-('i-NHR wherein R is a monovalent organic radicalselected from the group consisting of alkyl, substituted alkyl, aryl,and substituted aryl. This group of amides is substantiallynon-phytotoxic to higher plant life but is quite toxic to fungi andbacteria including several plant and animal parasitic species such asAlternaria solani.

Examples of this first group of amides which are new compositions ofmatter include the N-methyl, N-ethyl, N- propyl, N-butyl, N-amyl,N-hexyl, N-heptyl, N-octyl, N- nonyl, N-decyl, N-dodecyl, N-stearyl,N-heptadecyl, N- phenyl, N-chlorophenyl, N-dichlorophenyl, N-tolyl, N-xylidyl, N-chlorotolyl, N-nitrophenyl, N-naphthyl, N-furfuryl,N-picolinyl, N-benzyl, lI-cyclohexyl, N-cycloheptyl and N-cyclooctyltrichloro-Z-furamides and their halogen, nitro and loweralkyl-substituted analogues. These examples are not exhaustive butmerely illustrative of these inventive compositions. A preferred groupof these latter fungicides having superior fungicidal activity ascompared to the broad class as a whole are those having more than fourcarbon atoms, in the group R The second group of amide products of thisinvention are the trichloro-Z-furamides of the structure:

ll 01-0 0-0 -NRIRZ wherein R and R which may be the same or different,are either both hydrogen or are both monovalent radicals which may ormay not be co-joined to form cyclic structures. These compositions,which include the known unsubstituted amide (NR R is CONH surprisinglyenough, are highly phytotoxic to certain plants and thus are useful andvaluable as selective herbicides and plant growth regulants. None ofthese compositions including the known simple amide have been previouslydisclosed to have herbicidal utility. Examples of this second group ofstructures include but are not limited to the novel N,N- dimethyl,N-methyl-N-ethyl, N,N-diethyl, N,N-dipropyl, N,N-diisopropyl,N,N-dibutyl, N,N-'dioctyl, N,N-didecyl N-ethyl-N-phenyl, N-methyl-N (2hydroxyethyl) trichloro-Z-furamides as well as the piperidide,pyrrolidide, morpholide, mono and bis-piperazide, N,N'-piperazide,N-methylpiperazide and thiomorpholide of trichloro-2 furoic acid. Yetanother valuable but unrelated herbicide which can be made from thenovel acid chloride of the invention is 3,4-dichloro-2-furamide. Thiscan be accomplished by reduction of the trichloro-Z-furamide, forexample, by zinc in ammoniacal alcohol, by sodium amalgam or by hydrogenin the presence of a suitable catalyst such as platinum, palladium, ornickel. The rates of application and methods of formulation of3,4-dichloro- Z-furamide differ very little from those of trichloro-2-furamide. The principal point of advantage of 3,4-dichloro-2-furamideover trichloro-2-furamide is enhanced activity pre-emergence on wildoats, a major weed of Northern United States and Canada.

That the biological activity of the two groups of amides would be socritically dependent on the nature of the NR R moiety is most surprisingand unexpected, in view of the biological innocuousness of thetrichloro-Z- furoic acid and esters. No reason or mechanism issuggrasses, etc.

4 gested for the surprising biological activity of these compounds.

Both of these groups of biologically active amides may be used for theiragronomical uses in various grades of purity ranging from the highlypurified oils or crystalline products to a technical-reaction crude.Furthermore, these biological compositions offer the advantage ofcompatibility with a host of other biologically active substancesincluding herbicides in the tri and tetra-chlorophenylacetic acids andthe sodium borates and calcium borates, 2,4-D and other herbicidalphenoxy aliphatic acids and esters, simazine and other herbicidaltriazines, monuron, fenuron, diuron and other herbicidal ureas,herbicidal chlorates, petroleum oil's, hexachlorocyclopentadiene,pentachlorophenol, dinitro-o-alkylphenols, sodium trichloroacetate, andsodium 2,2-dichloropropionate, with fungicides such as the metaldimethyldithiocarbamates and ethylenebis-(dithiocarbamates), withinsecticides such as benzene hexachloride, DDT, chlordane and theinsecticidal carbamates, with fertilizers such as urea and ammoniumnitrate, and various adjuvants and diluents well known to the art. Thus,these biocides may be used by themselves or made the subject of liquidor solid formulations ranging from the very simple to the most complex.For example, if it is desired these compositions may be made the subjectof a liquid formulation by diluting, dispersing, dissolving oremulsifying with a surface active adjuvant or combination of theseadjuvants in water or organic solvents such as petroleum hydrocarbons,alcohols, ketones, esters, glycols or combinations thereof. Oralternatively, the novel herbicides may be made up as solid formulationsor powders, dusts, wettable dusts, granules and pellets using soliddiluents such as talcs, clays, flours, starches, diatomaceous earths,mica, limes, carbonates and phosphates either finely divided, granularor pelleted in form.

These solid and liquid formulations facilitate handling and applicationand sometimes enhance herbicidal activity to more than an additivedegree.

The liquid compositions, whether solutions or dispersions of the activeagents in a liquid solvent and also the wettable powder or dustcompositions of this invention may contain as a conditioning agent oneor more surface active agents in amounts sufficient to'render thecomposition readily dispersible in water. By the term surface activeagents are included wetting agents, dispersing agents, emulsifyingagents and the like. A satisfactory but not complete list of such agentsis set forth in an article in Soap and Chemical Specialties, vol. 31,No. 7, pages 50-61; No. 8, pages 48-61; No. 9, pages 52 67, and No. 10,pages 38 (67), 1955. Other sources of adjuvant materials are set forthin Bulletin E-607 of the Bureau of Entomology and Plant Quarantine ofthe United States Department of Agriculture.

While the manner and method of application of the inventive compositionsis varied and largely dependent upon variables such as the climaticconditions, crop treated, the weeds to be eradicated, the equipmentavailable and the convenience of the user, a preferred embodiment ofthis invention is to apply these biocides as a spray after making themup as a liquid' formulation comprised of several times their weight ofnon-phytotoxic carriers such as clay with small quantities of a wettingagent such as a commercial sodium alkylnaphthalene sulfonate and adispersing agent such as a lignin sulfonate. For example, when thesecond group of amides are used as herbicides they are mixed as aboveand dispersed in water and sprayed pre-emergence in the area to be usedfor growing the desired crop such as onions, radishes, turf Oralternatively, these compositions may be applied as a solid granularformulation. When used as fungicides the fungicidal compositions areapplied to the foliage to be protected.

The rate of application as either fungicide or herbicide cannot beprecisely stated due to factors such as the varying degree of resistancepossessed by the past species and crop,'the stage of growth, the soiltype and climatic conditions, but in general, the rate-s as a herbicidewill be at least one-quarter of a pound of amide per acre and forreasons of cost will seldom exceed one hundred pounds per acre with thepreferred range falling within one-half to fifty pounds per acre. Wherethe weeds are in an early stage of growth, they being more susceptible,will frequently respond to the rates from one-half to four pounds peracre while older weeds or weeds that are to be totally eradicated fromornamental beds or turf may require rates in excess of four pounds peracre. In those instances where the weed population has been allowed toaccumulate unchecked or where mature plants are en countered,applications of up to fifty and even beyond this rate may be required.For eradication of deeplyrooted herbicide-resistant perennial weeds suchas field bindweed, rates of ten to one hundred pounds are found best.When used as a fungicide, the rate of application will generally varybetween 0.25 and ten pounds per acre.

The process of preparing the trichloro-Z-furoyl chloride of thisinvention may be performed using a broad range of conditions. It may berun conveniently at sub or super or atmospheric pressures. The advantageof using superatmospheric conditions is that the reaction is acceleratedrequiring less time for completion. However, the gain in lessenedreaction time is offset by the necessity of using more intricateequipment and introducing attendant safety hazards. For these reasonsamong others, atmospheric pressures are preferred.

Our novel process for preparing trichloro-Z-furoyl chloride is mostconveniently performed at temperatures where the starting materialtetrachlorocoumalin will reflux. At pressures at or near atmospheric,this will be initially in the range of two hundred to two hundred andfifty degrees centrigrade. The boiling point will, of course, shift asthe reactions proceed, and as stated before, if desired, the boilingpoint can be raised by using superatmospheric pressures.

While there is considerable latitude as to the time of heating thetetrachlorocoumalin to effect standard conversion, at atmosphericpressures and at reflux the rearrangement will require from three hoursto fortyeight hours for substantial formation of the desiredtrichl-oro-Z-furoyl chloride, depending upon whether sub or superatmospheric pressure is used, higher pressures favoring the shorterreaction time and lower pressures the longer times. The preferredembodiment is to heat the tetrachlorocoumalin at atmospheric pressure atits reflux temperature from five to twelve hours, during which timesubstantial conversion takes place. While the type of reaction vessel isnot essential to the performance of this inventive process, certainadvantages may be gained through the use of modifications andelaborations in the reaction vessel. For example, it is convenient tocarry out the reaction in a vessel fitted with a means for fractionating so that the product can be distilled off as it is formed. Thisis possible since the trichloro-Z-furoyl chloride is lower boiling thanthe starting material tetrachlorocoumalin. Of alteratively, thetetrachlorocoumalin and trichloro-Z-furoyl chloride that is formed maybe refluxed together for a period of time necessary for substantialconversion to have taken place. This at atmospheric pressure will takebetween ten to twentyfour hours. Then the reaction mixture containingsome unreacted starting material as well as product is resolved throughfiltration or centrifugation. The usual adjuvants such as filter aids oractivated carbon may be added if desired. Facilitation of the separationof the product may be obtained in this modification by adding asufiicient amount of a solvent to remove either of the two components asan extract or filtrate.- For example, petroleum ether, among othersolvents, readily dissolves the product but is a poor solvent for thestarting material 6 and may thus expeditiously be added at this time.Improved yields are obtained in the reaction if air is excluded, toavoid oxidative side reactions.

The following examples are intended to illustrate the workings of thisinvention including such facets as the preparation of the pesticidalcompositions, their formulation as herbicidal and fungicidal agents andthe testing results obtained using these compounds. Except as set forthin the claims, these examples shallonly serve to illustrate theinvention and not limit it.

Example 1.Preparatz 0n 0f trz'chloro-Z-furoyl chloride To a three-literflask fitted with a four foot fractionating column topped with a stillhead provided with means for controlling the reflux ratio is added threethousand, one hundred and fifty parts by weight of tetrachlorocoumalinprepared by the methtod of Roedig et a1. (loc. cit.). gen atmosphere forone hour until the still head temperature dropped to about one hundredand seventy-seven degrees centrigrade. The product is taken off at 20:1reflux ratio over the course of thirty-six hours, until the pottemperature reaches three hundred and forty degrees centrigrade. At thispoint the distillation is stopped and the distillate collected andweighed. The colorless distillate is found by comparison of its infraredspectrum to a known sample to contain about eighty-two percent of thedesired trichloro-Z-furoyl chloride. The product is further purified byrepeated low-temperature recrystallizations from hexane in which theproduct is soluble at room temperature. The several times recrystallizedproduct melted at thirty-four degrees.

Analysis.-Calcd. for C Cl O Found: Cl, 60.5 percent.

The structure of the product is confirmed by comparing its hydrolysisproduct to the known trichloro-Z-furoic acid which has a melting pointof one hundred and seventy-four to one hundred and seventy-five degreescentigrade. (Hill and Jackson, Am. Chem. I. 12, 119 (1890).) V Themelting point of the hydrolysis product of the acid chloride of theinvention is identical to that of the known trichloro-Z-furoic acid, amixed melting point was undepressed, and the infrared spectra wereidentical. The trichloro-Z-furoyl chloride of the invention also yieldedan amide of melting point one hundred and sixtytwo to one hundred andsixty-three degrees identical to the known trichloro-2-furamide and anethyl ester of melting point sixty-three degrees, identical to the knownethyl trichloro-Z-furoate.

Example 2.Preparatiol z of trichloro-Z-furtlmide from trichloro-Z-furoylchloride Cl, 60.7 percent.

Gaseous ammonia is bubbled through a solution of two hundred andthirty-four grams of trichlorofuroyl chloride in one liter of benzene attwenty degrees centigrade, until the contents are saturated withammonia. After about two hours, the reaction mixture is filtered and thesolids washed with water to remove ammonium chloride. The remaininginsoluble product is recrystallized from methanol to obtain a yield oftwo hundred and eight grams of colorless crystalline solid, meltingpoint one hundred and sixty-two to one hundred and sixty three degrees.

Analysis.Calcd. for C H O Cl N: C1, 49.7 percent; N, 6.5 percent. Found:CI, 49.6 percent; N, 6.5 percent.

Examples 3-36.Preparati0n 0f N-substituted trichloro- Z-furamides (C C1OCONR R To a solution of trichloro-Z-furoyl chloride in dry benzene isadded two molar equivalents of the desired amine. After two hours at tento fifteen degrees centigrade the solution was Washed with water toremove the amine hydrochloride, dried and the solvent distilled off. Theresulting materials are recrystallized from alcohol, petroleum ether orbenzene.

The compound is heated to reflux under a nitrofiltered to obtain a tansolid having approximately the correct sulfur content'fortrichloro-Z-thiofuramide. A sharp melting point could not be obtainedbecause of a persistent impurity..

Example 36.3,4-dichlor-2-faramide Example 37 An area infested with wildoats (Avena fatua), is sprayed at the rate of six pounds per acre, priorto oat emergence, with 3,4-dichloro-2-furamide in wettable powdersuspension. One month later, substantially complete wild oat control isobserved in the treated area. Partial control (about fifty percent), isobtained with trichloro-Z- furamide at the same rate.

Example 38 Areas seeded to various weeds and crops are sprayed beforeemergence with various of the chemicals of the invention, at the rate ofsixteen pounds per acre. The

suppression of the various species was recorded two to three weekslater.

TABLE I Example M.P., Percent Percent No. R1 R C. N

Oalcd. Found Methyl s. 2 e. 2 Isopropyl 5. 5 5. O n-ButyL- 5. 2 5. 1t-Butyl. 5. 2 5. 2 n-0ctyl 4.3 4.3 Cyclohexyl 4. 7 4. 4 EF -an"- 22 t; Hrox e en l 4.8 4.7 o-Ohlorophenyl- 4. 31 4. 2 m-Chlorophenyl 4. 3 4. 2p-Ohl0rophenyl 4.3 4.2 3,4-dichlorophenyl 3. 9 3. 8 2carboxyphenyl. H4.2 4.2 5.8 5.8 5.2 5.1 4.7 4.6 4.7 4.1 4.3 3.8 4.3 3.3 Hexyl 3. 7 3. 42-ethylhexyl 2. 4 2. 9 Phenyl 81-82. 5 4. e 4. 6 do 47-9 4. 4 4. 42-hydroxyethyl 5. 2 4. 7 do 98-99. 5 4. s 4.6 Ally Allyl 113-115 4. s 4.9 bis(Ethylene) 226-9 6. 2 5. 2 N -methylpiperazide- 9. 4 9. 3N-phenylpiperazide 7. 8 8. 9 Morpholide 79 5431.5 4.9 4.3 Piperidide-37-38 4. 5 4. 5

011. 2 Low melting solid. I

Example 35.-Trichl0r0-2-thionofaramide TABLE H Trichloro-Z-furamide isheated with phosphorus pent- Hekbicridal I oxideand distilled to obtaina good yield of tri chloro-2 Compound f Com Radish 8 Pig-Lambsfuronitrile, a crystalline SOlld, melting point th1rty-three 35 Exaple F0 or b weed quarters to thirty-four degrees. i' g Analysis.Calcd.for C H Cl ONS: N, 7.1 percent. Found: N, 7.0 percent. 2 o 4 4 4 4Trichloro-Z-furonitrile is dissolved in pyridine and one g g g 4 3 3molar equivalent of trimethyl amine and water bubbled 3+ 0 3 2 g 2through for nine hours. Water is added and the mixture 0 0 3 3 3 2Rating Scale: 0=no efiect; l=slight suppression; 2=moderate suppression;3=almost complete suppression; 4=comp1ete suppression.

Example 39 A typical emulsifiable oil formulation is the following:

Parts by weight N,N-Diisopropyl-3,4,S-trichloro-Z-furamide 10 Atloxemulsifier (polyoxyethylene sorbitan ester) 2 High aromatic naphtha 20The ingredients are blended to obtain an oil emulsifiable with water,and which can be sprayed as an emulsion.

Example 40 A typical wettable powder formulation is the following:

, Parts by weight Trichloro-Z-furamide 25 Attapulgus clay 69 Sorbit P(commercial wetting agent) 1 Marasperse N (commercial dispersing agent)5 The ingredients are ground together in a hammer mill to prepare apowder which disperses upon agitation with water, and Which can besprayed as a suspension.

The amide is dissolved in acetone, the solution admixed with thevermiculite, and the granules dried to remove the acetone. Theformulation is applied by use of, a spreader or by hand.

9 Example 42 A typical mixed pesticide-fertilizer formulation for turfis the following:

Parts by weight Fertilizer 992 Trichloro-Z-furamide 62,4-dichlorophenoxyacetic acid 2 Example 43 TABLE III Compound ofexample No. Crabgrass Weed spe- Lambscies dock quarters Scale: =noeffect; 1=slight damage; 2=moderate damage; 3=severe damage; 4=eompletekill.

The compounds of the invention have utility also as fungicides and aschemical intermediates. In the latter regard, the halogen atoms on thefuran ring may be replaced by nucleophilic reagents to introducealkylamino, arylamino, amino, alkylmercapto, arylmercapto and othersubstituents, many of these products also having pesticidal activity.One or both of the double bonds in the furan ring may also be saturatedby chlorine or bromine to produce more highly halogenated products alsohaving in many cases pesti-cidal activity. The fungicidal activity ofthe compounds of the invention is of greatest value in the case of thosecompounds having relatively less phytotoxicity, since the major use forfungicides is on living plants. The following example illustrates thefungicidal activity of compounds of the invention.

10 Example 44 The compounds of Examples 7, 11 and 13 were pulverized anddispersed in water at the concentration of 0.1 percent. Tomato plantsinfested with Alternaria solani, (the causative organism of early blightdisease), were sprayed with these suspensions. At a later time, whensimilarly infected but unsprayed plants had developed, severe diseasesymptoms, the development of disease symptoms on the treated plants wassubstantially repressed.

What is claimed is:

1. A method of controlling fungicidal plant diseases which comprisesapplying to the plant to be treated a fungicidal amount of a compound ofthe structure:

wherein R is a monovalent organic radical selected from the groupconsisting of alkyl of one to eighteen carbon atoms; alkyl of one toeighteen carbon atoms substituted by a radical selected from the groupconsisting of halogen and nitro; phenyl; phenyl substituted by a radicalselected from the group consisting of halogen, nitro and lower alkyl;naphthyl; furfuryl; picolinyl; benzyl; and cycloalkyl of from six toeight carbon atoms.

2. A method according to claim 1 where R is selected from the groupconsisting of alkyl of one to eighteen carbon atoms; alkyl of one toeightheen carbon atoms substituted by a radical selected from the groupconsisting of chlorine and nitro; phenyl; phenyl substituted by aradical selected from the group consisting of chlorine, nitro and loweralkyl; naphthyl; furfuryl; picolinyl; benZyl; and cycloalkyl of from sixto eight carbon atoms.

No references cited.

JULIAN S. LEVlTT, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,253,982 May 31, 1966 Edward Leon et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

In the heading to the printed specification, line 2, for "EUNGICIDAL"read FUNGAL column 3, line 44, for

"(NR R is CONHZ)" read -NR R is NHZ column 9, TABLE III, the headingsthereof should appear as shown below instead of as in the patent:

TABLE III Weed Species Compound of Example No. Crabgrass DockLambsquarters column 10, line 12, for "fungicidal" read fungal line 29,for "where" read wherein line 31, for "eightheen" read eighteen Signedand sealed this 10th day of October 1967.

(SEAL) Attest:

EDWARD M. FLETCHER,JR. Attesting Officer EDWARD J BRENNER Commissionerof Patents

1. A METHOD OF CONTROLLING FUNGICIDAL PLANT DISEASES WHICH COMPRISESAPPLYING TO THE PLANT TO BE TREATED A FUNGICIDAL AMOUNT OF A COMPOUND OFTHE STRUCTURE: